#include <stdlib.h>
#include <math.h>
#include <float.h>
+#include <assert.h>
#include "geom.h"
#include "matrix.h"
return ray_cylinder(ray, o);
case OB_PLANE:
return ray_plane(ray, o);
+ case OB_BOX:
+ return ray_box(ray, o);
case OB_UNION:
return ray_csg_un(ray, o);
case OB_INTERSECTION:
return hit;
}
+static int ray_cylcap(struct ray *ray, float y, float rad, float *tres)
+{
+ float ndotr, ndotv, vy, t;
+ float ny = y > 0.0f ? 1.0f : -1.0f;
+ float x, z, lensq;
+
+ ndotr = ny * ray->dy;
+ if(fabs(ndotr) < EPSILON) return 0;
+
+ vy = y - ray->y;
+
+ ndotv = ny * vy;
+
+ t = ndotv / ndotr;
+
+ x = ray->x + ray->dx * t;
+ z = ray->z + ray->dz * t;
+ lensq = x * x + z * z;
+
+ if(lensq <= rad * rad) {
+ *tres = t;
+ return 1;
+ }
+ return 0;
+}
+
struct hinterv *ray_cylinder(struct ray *ray, csg_object *o)
{
+ int i, out[2] = {0}, t_is_cap[2] = {0};
+ float a, b, c, d, sqrt_d, t[2], sq_rad, tmp, y[2], hh, cap_t;
+ struct hinterv *hit;
struct ray locray = *ray;
+ if(o->cyl.rad == 0.0f || o->cyl.height == 0.0f) {
+ return 0;
+ }
+ sq_rad = o->cyl.rad * o->cyl.rad;
+ hh = o->cyl.height / 2.0f;
+
xform_ray(&locray, o->ob.inv_xform);
- return 0; /* TODO */
+
+ a = locray.dx * locray.dx + locray.dz * locray.dz;
+ b = 2.0f * (locray.dx * locray.x + locray.dz * locray.z);
+ c = locray.x * locray.x + locray.z * locray.z - sq_rad;
+
+ d = b * b - 4.0f * a * c;
+ if(d < EPSILON) return 0;
+
+ sqrt_d = sqrt(d);
+ t[0] = (-b + sqrt_d) / (2.0f * a);
+ t[1] = (-b - sqrt_d) / (2.0f * a);
+
+ if(t[0] < EPSILON && t[1] < EPSILON) {
+ return 0;
+ }
+ if(t[1] < t[0]) {
+ tmp = t[0];
+ t[0] = t[1];
+ t[1] = tmp;
+ }
+
+ y[0] = locray.y + locray.dy * t[0];
+ y[1] = locray.y + locray.dy * t[1];
+
+ if(y[0] < -hh || y[0] > hh) {
+ out[0] = 1;
+ }
+ if(y[1] < -hh || y[1] > hh) {
+ out[1] = 1;
+ }
+
+ if(out[0]) {
+ t[0] = t[1];
+ }
+ if(out[1]) {
+ t[1] = t[0];
+ }
+
+ if(ray_cylcap(ray, hh, o->cyl.rad, &cap_t)) {
+ if(cap_t < t[0]) {
+ t[0] = cap_t;
+ t_is_cap[0] = 1;
+ out[0] = 0;
+ }
+ if(cap_t > t[1]) {
+ t[1] = cap_t;
+ t_is_cap[1] = 1;
+ out[1] = 0;
+ }
+ }
+ if(ray_cylcap(ray, -hh, o->cyl.rad, &cap_t)) {
+ if(cap_t < t[0]) {
+ t[0] = cap_t;
+ t_is_cap[0] = -1;
+ out[0] = 0;
+ }
+ if(cap_t > t[1]) {
+ t[1] = cap_t;
+ t_is_cap[1] = -1;
+ out[1] = 0;
+ }
+ }
+
+ if(out[0] && out[1]) {
+ return 0;
+ }
+
+ hit = alloc_hits(1);
+ hit->o = o;
+ for(i=0; i<2; i++) {
+ float c[3] = {0, 0, 0};
+ float x, y, z;
+
+ x = ray->x + ray->dx * t[i];
+ y = ray->y + ray->dy * t[i];
+ z = ray->z + ray->dz * t[i];
+
+ if(t_is_cap[i]) {
+ hit->end[i].nx = hit->end[i].nz = 0.0f;
+ hit->end[i].ny = t_is_cap[i] > 0 ? 1.0f : -1.0f;
+ } else {
+ c[1] = locray.y + locray.dy * t[i];
+ mat4_xform3(c, o->ob.xform, c);
+
+ hit->end[i].nx = (x - c[0]) / o->cyl.rad;
+ hit->end[i].ny = (y - c[1]) / o->cyl.rad;
+ hit->end[i].nz = (z - c[2]) / o->cyl.rad;
+ }
+
+ hit->end[i].t = t[i];
+ hit->end[i].x = x;
+ hit->end[i].y = y;
+ hit->end[i].z = z;
+ hit->end[i].o = o;
+ }
+ return hit;
}
struct hinterv *ray_plane(struct ray *ray, csg_object *o)
return hit;
}
+#define BEXT(x) ((x) * 0.49999)
+
+struct hinterv *ray_box(struct ray *ray, csg_object *o)
+{
+ int i, sign[3];
+ float param[2][3];
+ float inv_dir[3];
+ float tmin, tmax, tymin, tymax, tzmin, tzmax;
+ struct hinterv *hit;
+ struct ray locray = *ray;
+ float dirmat[16];
+
+ xform_ray(&locray, o->ob.inv_xform);
+
+ for(i=0; i<3; i++) {
+ float sz = *(&o->box.xsz + i);
+ param[0][i] = -0.5 * sz;
+ param[1][i] = 0.5 * sz;
+
+ inv_dir[i] = 1.0f / *(&locray.dx + i);
+ sign[i] = inv_dir[i] < 0;
+ }
+
+ tmin = (param[sign[0]][0] - locray.x) * inv_dir[0];
+ tmax = (param[1 - sign[0]][0] - locray.x) * inv_dir[0];
+ tymin = (param[sign[1]][1] - locray.y) * inv_dir[1];
+ tymax = (param[1 - sign[1]][1] - locray.y) * inv_dir[1];
+
+ if(tmin > tymax || tymin > tmax) {
+ return 0;
+ }
+ if(tymin > tmin) {
+ tmin = tymin;
+ }
+ if(tymax < tmax) {
+ tmax = tymax;
+ }
+
+ tzmin = (param[sign[2]][2] - locray.z) * inv_dir[2];
+ tzmax = (param[1 - sign[2]][2] - locray.z) * inv_dir[2];
+
+ if(tmin > tzmax || tzmin > tmax) {
+ return 0;
+ }
+ if(tzmin > tmin) {
+ tmin = tzmin;
+ }
+ if(tzmax < tmax) {
+ tmax = tzmax;
+ }
+
+ mat4_copy(dirmat, o->ob.xform);
+ mat4_upper3x3(dirmat);
+
+ hit = alloc_hits(1);
+ hit->o = o;
+ for(i=0; i<2; i++) {
+ float n[3] = {0};
+ float t = i == 0 ? tmin : tmax;
+
+ float x = (locray.x + locray.dx * t) / o->box.xsz;
+ float y = (locray.y + locray.dy * t) / o->box.ysz;
+ float z = (locray.z + locray.dz * t) / o->box.zsz;
+
+ if(fabs(x) > fabs(y) && fabs(x) > fabs(z)) {
+ n[0] = x > 0.0f ? 1.0f : -1.0f;
+ } else if(fabs(y) > fabs(z)) {
+ n[1] = y > 0.0f ? 1.0f : -1.0f;
+ } else {
+ n[2] = z > 0.0f ? 1.0f : -1.0f;
+ }
+
+ hit->end[i].o = o;
+ hit->end[i].t = t;
+ hit->end[i].x = ray->x + ray->dx * t;
+ hit->end[i].y = ray->y + ray->dy * t;
+ hit->end[i].z = ray->z + ray->dz * t;
+ mat4_xform3(&hit->end[i].nx, dirmat, n);
+ }
+ return hit;
+}
+
struct hinterv *ray_csg_un(struct ray *ray, csg_object *o)
{
struct hinterv *hita, *hitb, *res;
projects / csgray / blobdiff